MPI ranks not spawning threads specified via OMP_NUM_THREADS

Hi,
I am trying to attempt a run of mr weather application with C96 resolution , 32 ranks and 4 threads per rank. here is the contents of  env_mach_specific.xml - 
  <environment_variables>
    <env name="OMP_STACKSIZE">256M</env>
    <env name="OMP_NUM_THREADS">4</env>
  </environment_variables>

This is what i get with   ./pelayout -
Comp  NTASKS  NTHRDS  ROOTPE
ATM :     32/     4;      0

output of ./preview_run
CASE INFO:
  nodes: 1
  total tasks: 32
  tasks per node: 32
  thread count: 4

BATCH INFO:
  FOR JOB: case.chgres
    ENV:
Setting Environment OMP_STACKSIZE=256M
Setting Environment OMP_NUM_THREADS=4
      Setting Environment OMP_NUM_THREADS=4

    SUBMIT CMD:
      sbatch  .case.chgres

  FOR JOB: case.run
    ENV:
Setting Environment OMP_STACKSIZE=256M
Setting Environment OMP_NUM_THREADS=4
      Setting Environment OMP_NUM_THREADS=4

    SUBMIT CMD:
      sbatch --dependency=afterok:0 .case.run --resubmit

    MPIRUN (job=case.run):
      mpirun  -np 32 -prepend-rank /work/puneet/MyWork/Milan_UFStry01/1.1.0_intel/src3/run3/DORIAN_C96_GFSv15p2_2.2.6.8.1/bld/ufs.exe   >> ufs.log.$LID 2>&1

  FOR JOB: case.gfs_post
    .....

had also added the  export OMP_NUM_THREADS=4 in my .bashrc.
i monitored the compute node for the entire duration of run. I am able to see 32 MPI ranks, but however they did not spawn threads -

556144 user1    20   0 9499396 621120  42344 R 100.0   0.2   6:57.41 ufs.exe
556147 user1    20   0 9486968 622796  42424 R 100.0   0.2   6:57.55 ufs.exe
556134 user1    20   0 9505012 633764  41388 R  99.7   0.2   6:57.45 ufs.exe
556135 user1    20   0 9499528 621256  41420 R  99.7   0.2   6:57.41 ufs.exe
556136 user1    20   0 9487352 621628  41240 R  99.7   0.2   6:57.43 ufs.exe
556137 user1    20   0 9500096 619976  41708 R  99.7   0.2   6:57.44 ufs.exe
556138 user1    20   0 9611392 737904  42640 R  99.7   0.3   6:57.41 ufs.exe
556139 user1    20   0 9602168 723396  42452 R  99.7   0.3   6:57.47 ufs.exe
556140 user1    20   0 9602180 722400  41208 R  99.7   0.3   6:57.44 ufs.exe
556142 user1    20   0 9518612 636016  42804 R  99.7   0.2   6:57.39 ufs.exe
556143 user1    20   0 9500148 622756  42264 R  99.7   0.2   6:57.43 ufs.exe
556145 user1    20   0 9500692 622196  42320 R  99.7   0.2   6:57.44 ufs.exe
556148 user1    20   0 9496480 621540  43032 R  99.7   0.2   6:57.56 ufs.exe
556149 user1    20   0 9492664 620948  42792 R  99.7   0.2   6:57.58 ufs.exe
556150 user1    20   0 9621468 738080  43456 R  99.7   0.3   6:57.54 ufs.exe
556151 user1    20   0 9608276 725308  42400 R  99.7   0.3   6:57.59 ufs.exe
556152 user1    20   0 9607844 723220  42756 R  99.7   0.3   6:57.60 ufs.exe
556154 user1    20   0 9908108 960328  31276 R  99.7   0.4   6:58.31 ufs.exe
556155 user1    20   0 9893060 953720  30352 R  99.7   0.4   6:58.35 ufs.exe
556156 user1    20   0 9893060 953660  30108 R  99.7   0.4   6:58.32 ufs.exe
556157 user1    20   0 9884676 951744  28972 R  99.7   0.4   6:58.34 ufs.exe
556158 user1    20   0 9892040 951760  29216 R  99.7   0.4   6:58.50 ufs.exe
556159 user1    20   0 9887844 950892  28988 R  99.7   0.4   6:58.50 ufs.exe
556160 user1    20   0 9892044 951116  29208 R  99.7   0.4   6:58.50 ufs.exe
556161 user1    20   0 9887844 950340  29024 R  99.7   0.4   6:58.33 ufs.exe
556130 user1    20   0 9539632 637796  42152 R  99.3   0.2   6:57.45 ufs.exe
556131 user1    20   0 9511956 621072  41996 R  99.3   0.2   6:57.42 ufs.exe
556132 user1    20   0 9495644 620852  40912 R  99.3   0.2   6:57.39 ufs.exe
556133 user1    20   0 9521516 621592  41740 R  99.3   0.2   6:57.54 ufs.exe
556141 user1    20   0 9603692 728268  41904 R  99.3   0.3   6:56.86 ufs.exe
556146 user1    20   0 9506264 635568  43396 R  99.3   0.2   6:57.61 ufs.exe
556153 user1    20   0 9607984 724736  43104 R  99.3   0.3   6:57.57 ufs.exe
556280 user1    20   0   68852   5856   3728 R   0.7   0.0   0:02.65 top

Is there something which i need to set in config files to make this hybrid run to work?
please advice.